Re: [PATCH net-next 1/8] net/flower: Introduce hardware offload support

Jiri Pirko
2016-03-01T17:01:31Z

Tue, Mar 01, 2016 at 05:49:27PM CET, amir@vadai.me wrote:
>On Tue, Mar 01, 2016 at 03:47:19PM +0100, Jiri Pirko wrote:
>> Tue, Mar 01, 2016 at 03:24:43PM CET, amir@vadai.me wrote:
>> >This patch is based on a patch made by John Fastabend.
>> >It adds support for offloading cls_flower.
>> >A filter that is offloaded successfuly by hardware, will not be added to
>> >the hashtable and won't be processed by software.
>>
>> That is wrong. User should explitly specify to not include rule into sw
>> by SKIP_KERNEL flag (does not exist now, with John's recent patch we'll
>> have only SKIP_HW). Please add that in this patchset.
>Why? If a rule is offloaded, why would the user want to reprocess it by
>software?
>If the user use SKIP_HW, it will be processed by SW. Else, the user
>would want it to be processed by HW or fallback to SW. I don't
>understand in which case the user would like to have it done twice.

For example if you turn on the offloading by unsetting NETIF_F_HW_TC.
Or if someone inserts skbs into rx path directly, for example pktgen.
We need SKIP_KERNEL to be set by user, not implicit.